Congenital Generalized Lipodystrophy Type Research Articles

Identification of genetic suppressors for a BSCL2 lipodystrophy pathogenic variant in Caenorhabditis elegans.

Seipin (BSCL2), a conserved endoplasmic reticulum protein, plays a critical role in lipid droplet (LD) biogenesis and in regulating LD morphology, pathogenic variants of which are associated with Berardinelli-Seip congenital generalized lipodystrophy type 2 (BSCL2). To model BSCL2 disease, we generated an orthologous BSCL2 variant, seip-1(A185P), in Caenorhabditis elegans. In this study, we conducted an unbiased chemical mutagenesis screen to identify genetic suppressors that restore embryonic viability in the seip-1(A185P) mutant background. A total of five suppressor lines were isolated and recovered from the screen. The defective phenotypes of seip-1(A185P), including embryonic lethality and impaired eggshell formation, were significantly suppressed in each suppressor line. Two of the five suppressor lines also alleviated the enlarged LDs in the oocytes. We then mapped a suppressor candidate gene, lmbr-1, which is an ortholog of human limb development membrane protein 1 (LMBR1). The CRISPR/Cas9 edited lmbr-1 suppressor alleles, lmbr-1(S647F) and lmbr-1(P314L), both significantly suppressed embryonic lethality and defective eggshell formation in the seip-1(A185P) background. The newly identified suppressor lines offer valuable insights into potential genetic interactors and pathways that may regulate seipin in the lipodystrophy model.

Metabolic and other morbid complications in congenital generalized lipodystrophy type 4.

Morbidity and mortality rates in patients with autosomal recessive, congenital generalized lipodystrophy type 4 (CGL4), an ultra-rare disorder, remain unclear. We report on 30 females and 16 males from 10 countries with biallelic null variants in CAVIN1 gene (mean age, 12 years; range, 2 months to 41 years). Hypertriglyceridemia was seen in 79% (34/43), hepatic steatosis in 82% (27/33) but diabetes mellitus in only 21% (8/44). Myopathy with elevated serum creatine kinase levels (346-3325 IU/L) affected all of them (38/38). 39% had scoliosis (10/26) and 57% had atlantoaxial instability (8/14). Cardiac arrhythmias were detected in 57% (20/35) and 46% had ventricular tachycardia (16/35). Congenital pyloric stenosis was diagnosed in 39% (18/46), 9 had esophageal dysmotility and 19 had intestinal dysmotility. Four patients suffered from intestinal perforations. Seven patients died at mean age of 17 years (range: 2 months to 39 years). The cause of death in four patients was cardiac arrhythmia and sudden death, while others died of prematurity, gastrointestinal perforation, and infected foot ulcers leading to sepsis. Our study highlights high prevalence of myopathy, metabolic abnormalities, cardiac, and gastrointestinal problems in patients with CGL4. CGL4 patients are at high risk of early death mainly caused by cardiac arrhythmias.

Metreleptin Treatment in a Boy with Congenital Generalized Lipodystrophy due to Homozygous c.465_468delGACT (p.T156Rfs*8) Mutation in the BSCL2 Gene; The First-year Results.

Congenital generalized lipodystrophy (CGL) is a rare autosomal recessive disorder characterized by an almost complete absence of body fat. In CGL, patients may have hyperphagia due to leptin deficiency. Recombinant human leptin (metreleptin) has been suggested as an effective treatment option. We, herein, present the successful use of metreleptin in a case with CGL and its 1-year follow-up. An eight-month-old boy presented with complaints of hair growth and muscular appearance: He had, hypertrichosis, decreased subcutaneous adipose tissue in the whole body and hepatomegaly. In the laboratory investigations hypertriglyceridemia, hyperinsulinemia, elevated liver transaminases and low leptin levels were detected. In molecular genetic analysis homozygous c.465_468delGACT (p.T156Rfs*8) mutation was detected in the BSCL2 gene. A diagnosis of CGL type 2 was considered. Despite the dietary intervention, exercises, omega-3 and metformin treatment, the hypertriglyceridemia, hyperinsulinemia, and elevated liver transaminase levels worsened. After one year of metreleptin treatment, hyperphagia disappeared, insulin, HbA1c, triglyceride and liver transaminase levels improved dramatically. Hepatosteatosis reduced, The size of the liver and the spleen remarkably decreased. Metreleptin is an effective treatment option that prevents the development of metabolic complications of CGL in children. The initiation of metreleptin treatment in the early period would decrease mortality and morbidity, and increase the quality of life in children with CGL.

Gene therapy restores adipose tissue and metabolic health in a pre-clinical mouse model of lipodystrophy

Congenital generalized lipodystrophy type 2 is a serious multisystem disorder with limited treatment options. It is caused by mutations affecting the BSCL2 gene, which encodes the protein seipin. Patients with congenital generalized lipodystrophy type 2 lack both metabolic and mechanical adipose tissue and develop severe metabolic complications including hepatic steatosis, lipoatrophic diabetes, and cardiovascular disease. Gene therapies are becoming viable treatments, helping to alleviate inherited and acquired human disorders. We aimed to determine whether gene therapy could offer an effective form of medical intervention for lipodystrophy. We examined whether systemic adeno-associated virus delivery of human BSCL2 could reverse metabolic disease in seipin knockout mice, where white adipose tissue is absent. We reveal that adeno-associated virus gene therapy targets adipose progenitor cells invivo and substantially restores white adipose tissue development in adult seipin knockout mice. This resulted in both rapid and prolonged beneficial effects to metabolic health in this pre-clinicalmouse model of congenital generalized lipodystrophy type 2. Hyperglycemia was normalized within 2weeks post-treatment together with normalization of severe insulin resistance. We propose that gene therapy offers great potential as a therapeutic strategy to correct multiple metabolic complications in patients with congenital lipodystrophy.

Reduced phosphatidylcholine synthesis suppresses the embryonic lethality of seipin deficiency

AbstractSeipin plays a vital role in lipid droplet homeostasis, and its deficiency causes congenital generalized lipodystrophy type II in humans. It is not known whether the physiological defects are all caused by cellular lipid droplet defects. Loss-of-function mutation of seip-1, the Caenorhabditis elegans seipin ortholog, causes embryonic lethality and lipid droplet abnormality. We uncover nhr-114 and spin-4 as two suppressors of seip-1 embryonic lethality. Mechanistically, nhr-114 and spin-4 act in the “B12-one-carbon cycle-phosphatidylcholine (PC)” axis, and reducing PC synthesis suppresses the embryonic lethality of seip-1 mutants. Conversely, PC deficiency enhances the lipid droplet abnormality of seip-1 mutants. The suppression of seip-1 embryonic lethality by PC reduction requires polyunsaturated fatty acid. In addition, the suppression is enhanced by the knockdown of phospholipid scramblase epg-3. Therefore, seipin and PC exhibit opposite actions in embryogenesis, while they function similarly in lipid droplet homeostasis. Our results demonstrate that seipin-mediated embryogenesis is independent of lipid droplet homeostasis.

The ecology of the microbiome in children with congenital generalized lipodystrophy type 4 (CGL4) is quickly modified after metreleptin treatment

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Successful treatment of severe hypertriglyceridemia with icosapent ethyl in a case of congenital generalized lipodystrophy type 4

Abstract Objectives Congenital generalized lipodystrophy type 4 (CGL4) is a rare autosomal recessive condition with high rates of morbidity and mortality. It is a multisystem condition associated with ventricular tachyarrhythmia, congenital myopathy, hepatitis, and metabolic profile of severe hypertriglyceridemia and insulin resistance. Metreleptin is the first line treatment, however it is unavailable in several countries. Herein, we describe a unique presentation and treatment of CGL4. Case presentation A 16-year-old female presented with insulin resistant diabetes, and was later found to have myopathy, hypertriglyceridemia, nonalcoholic fatty liver disease, ventricular arrhythmias, and genetic confirmation of CGL4 due to homozygous change in CAVIN1 gene. She had severe hypertriglyceridemia, frequently >17 mmol/L, requiring several hospital admissions. To better control hypertriglyceridemia, in context of known congenital myopathy, we opted for treatment with icosapent ethyl, an ethyl ester of eicosapentaenoic acid (EPA), which reduces synthesis and enhances clearance of triglycerides. On this treatment, she was able to maintain stable triglyceride levels of 4 mmol/L. Conclusions We present the first case report of a patient with CGL4, successfully treated for hypertriglyceridemia, with icosapent ethyl.

Bscl2 Deficiency Does Not Directly Impair the Innate Immune Response in a Murine Model of Generalized Lipodystrophy.

Congenital Generalized Lipodystrophy type 2 (CGL2) is the most severe form of lipodystrophy and is caused by mutations in the BSCL2 gene. Affected patients exhibit a near complete lack of adipose tissue and suffer severe metabolic disease. A recent study identified infection as a major cause of death in CGL2 patients, leading us to examine whether Bscl2 loss could directly affect the innate immune response. We generated a novel mouse model selectively lacking Bscl2 in the myeloid lineage (LysM-B2KO) and also examined the function of bone-marrow-derived macrophages (BMDM) isolated from global Bscl2 knockout (SKO) mice. LysM-B2KO mice failed to develop lipodystrophy and metabolic disease, providing a model to study the direct role of Bscl2 in myeloid lineage cells. Lipopolysaccharide-mediated stimulation of inflammatory cytokines was not impaired in LysM-B2KO mice or in BMDM isolated from either LysM-B2KO or SKO mice. Additionally, intracellular fate and clearance of bacteria in SKO BMDM challenged with Staphylococcus aureus was indistinguishable from that in BMDM isolated from littermate controls. Overall, our findings reveal that selective Bscl2 deficiency in macrophages does not critically impact the innate immune response to infection. Instead, an increased susceptibility to infection in CGL2 patients is likely to result from severe metabolic disease.

A novel AGPAT2 mutation associated with a case of late-diagnosed congenital generalized lipodystrophy type 1.

A novel AGPAT2 mutation associated with a case of late-diagnosed congenital generalized lipodystrophy type 1.

Identification of a novel AGPAT2 variant in a Chinese patient with congenital generalized lipodystrophy type 1

To explore the genetic basis for an infant with congenital generalized lipodystrophy. Peripheral blood samples of the child and her parents were collected for the extraction of genomic DNA. All exons and flanking sequences of the AGPAT2 gene were subjected to Sanger sequencing. The child was found to harbor compound heterozygous c.792_805delGGAGAACGGGGCCA (p.Gln264Hisfs*208) and c.335C>T (p.P112L) variants in exons 6 and 3 of the AGPAT2 gene, which were respectively inherited from her mother and father. c.792_805delGGAGAACGGGGCCA (p.Gln264Hisfs*208) was previously unreported, while c.335C>T (p.P112L) was known to be pathogenic. The compound heterozygous variants of the AGPAT2 gene probably underlie the disease in this child.

Absence of AGPAT2 impairs brown adipogenesis, increases IFN stimulated gene expression and alters mitochondrial morphology

BackgroundBiallelic loss of function variants in AGPAT2, encoding 1-acylglycerol-3-phosphate O-acyltransferase 2, cause congenital generalized lipodystrophy type 1, a disease characterized by near total loss of white adipose tissue and metabolic complications. Agpat2 deficient (Agpat2−/−) mice completely lacks both white and interscapular brown adipose tissue (iBAT). The objective of the present study was to characterize the effects of AGPAT2 deficiency in brown adipocyte differentiation. MethodsPreadipocytes obtained from newborn (P0.5) Agpat2−/− and wild type mice iBAT were differentiated into brown adipocytes, compared by RNA microarray, RT-qPCR, High-Content Screening (HCS), western blotting and electron microscopy. Results1) Differentiated Agpat2−/− brown adipocytes have fewer lipid-laden cells and lower abundance of Pparγ, Pparα, C/ebpα and Pgc1α, both at the mRNA and protein levels, compared those to wild type cells. Prmd16 levels were equivalent in both, Agpat2−/− and wild type, while Ucp1 was only induced in wild type cells, 2) These differences were not due to lower abundance of preadipocytes, 3) Differentiated Agpat2−/− brown adipocytes are enriched in the mRNA abundance of genes participating in interferon (IFN) type I response, whereas genes involved in mitochondrial homeostasis were decreased, 4) Mitochondria in differentiated Agpat2−/− brown adipocytes had altered morphology and lower mass and contacting sites with lipid droplets concomitant with lower levels of Mitofusin 2 and Perlipin 5. ConclusionAGPAT2 is necessary for normal brown adipose differentiation. Its absence results in a lower proportion of lipid-laden cells, increased expression of interferon-stimulated genes (ISGs) and alterations in mitochondrial morphology, mass and fewer mitochondria to lipid droplets contacting sites in differentiated brown adipocytes.

Homozygous LMNA p.R582H pathogenic variant reveals increasing effect on the severity of fat loss in lipodystrophy

BackgroundClassical heterozygous pathogenic variants of the lamin A/C (LMNA) gene cause autosomal dominant familial partial lipodystrophy type 2 (FPLD2). However, recent reports indicate phenotypic heterogeneity among carriers of LMNA pathogenic variants, and a few patients have been associated with generalized fat loss.Case presentationHere, we report a patient with a lamin A specific pathogenic variant in exon 11, denoted LMNA (c.1745G > A; p.R582H), present in the homozygous state. Fat distribution was compared radiographically to an unrelated heterozygote LMNA p.R582H patient from another pedigree, a healthy female control, a series of adult female subjects with congenital generalized lipodystrophy type 1 (CGL1, n = 9), and typical FPLD2 (n = 8). The whole-body MRI of the index case confirmed near-total loss of subcutaneous adipose tissue with well-preserved fat in the retroorbital area, palms and soles, mons pubis, and external genital region. This pattern resembled the fat loss pattern observed in CGL1 with only one difference: strikingly more fat was observed around mons pubis and the genital region. Also, the p.R582H LMNA variant in homozygous fashion was associated with lower leptin level and earlier onset of metabolic abnormalities compared to heterozygous p.R582H variant and typical FPLD2 cases. On the other hand, the heterozygous LMNA p.R582H variant was associated with partial fat loss which was similar to typical FPLD2 but less severe than the patients with the hot-spot variants at position 482.ConclusionsOur observations and radiological comparisons demonstrate an additive effect of LMNA pathogenic variants on the severity of fat loss and add to the body of evidence that there may be complex genotype-phenotype relationships in this interesting disease known as FPLD2. Although the pathological basis for fat loss is not well understood in patients harboring pathogenic variants in the LMNA gene, our observation suggests that genetic factors modulate the extent of fat loss in LMNA associated lipodystrophy.

Focus on progressive myoclonic epilepsy in Berardinelli-Seip syndrome

Berardinelli-Seip syndrome or congenital generalized lipodystrophy type 2 is a rare genetic disorder characterized by selective loss of subcutaneous adipose tissue associated with peripheral insulin resistance and its complications. Nonprogressive mental retardation, dystonia, ataxia, and pyramidal signs are commonly present, whereas epilepsy has only occasionally been observed. We report the case of two sisters, 11 and 18 years old respectively, with an overlapping clinical phenotype compatible with Berardinelli-Seip syndrome and progressive myoclonic epilepsy. Molecular analysis identified an autosomal recessive c.1048C > t;(p(Arg350*)) pathogenic mutation of exon 8 of the BSCL2 gene, which was present in a homozygous state in both patients. Our paper contributes to further delineate a complex phenotype associated with BSCL2 mutation, underlining how seipin has a central and partially still unknown role that goes beyond adipose tissue metabolism, with a prominent involvement in central nervous system pathology.

Unusual clinical features associated with congenital generalized lipodystrophy type 4 in a patient with a novel E211X CAVIN1 gene variant

BackgroundCongenital generalized lipodystrophy (CGL) is a rare disorder characterized by the lack of adipose tissue and metabolic complications with predominantly autosomal recessive inheritance. There are 6 different genes known to cause CGL with 4 main types recognized to date, which differ by the degree of fat loss, association with mental retardation and metabolic disorders, with CGL type 1 and 2 being the most common. Twenty seven cases of СGL type 4 from Japan, Oman, UK, Turkey, Mexico, Saudi Arabia, USA were reported previously. This report details our clinical experience with the first patient from Russia with CGL type 4.Case presentationA 36-year-old patient, who has been suffering from generalized lipoatrophy since the first months of life and myopathy and gastrointestinal dysmotility since early childhood, developed dysmenorrhea and diabetes mellitus at the age of 19, bilateral cataracts when she was only 22 y.o., osteoporosis with vitamin D deficiency and hypocalcemia at the age of 28, diabetic foot syndrome and hyperuricemia when she was 35 y.o. Sequencing of lipodystrophy candidate genes detected a novel pathogenic homozygous variant p.631G < T: p.E211X in the CAVIN1 gene, confirming the diagnosis of CGL type 4.ConclusionsIn comparison with previously reported patients with CGL type 4, our patient has diabetes mellitus, vitamin D deficiency, hypocalcemia, bilateral cataracts and hyperuricemia. All these manifestations are known to be associated with other lipodystrophy syndromes, but to our knowledge it is the first time they have been reported to be associated with CGL type 4.

SUN-600 Presence of LMNA p.R582H Pathogenic Variant in Homozygous State Demonstrates Gene Dosage Effect on the Severity of Fat Loss in Lipodystrophy

Background Classical heterozygous pathogenic variants of the lamin A/C (LMNA) gene cause familial partial lipodystrophy type 2 (FPLD2). However, recent reports indicate phenotypic heterogeneity among carriers of LMNA pathogenic variants, and a few patients have been associated with generalized fat loss. Clinical Case Here, we report a patient with lamin A specific pathogenic variant at exon 11 LMNA p.R582H present in homozygous state. Fat distribution was compared radiographically to a heterozygote LMNA p.R582H patient from another pedigree, female healthy control, a series of adult female subjects with congenital generalized lipodystrophy type 1 (CGL1, n = 9) and typical FPLD2 (n = 8). The whole body MRI of the index case confirmed near-total loss of subcutaneous adipose tissue with well-preserved fat in the retroorbital area, palms and soles, mons pubis, and external genital region. This pattern resembled the fat loss pattern observed in CGL1 with only one difference: strikingly more fat was observed around mons pubis and the genital region. Also, homozygous p.R582H LMNA variant was associated with lower leptin level and earlier onset of metabolic abnormalities compared to heterozygous p.R582H variant and typical FPLD2 cases. On the other hand, heterozygous LMNA p.R582H variant was associated with partial fat loss which was similar to typical FPLD2 but less severe than the patients with the hot-spot variants at position 482. Conclusions Our observations and radiological comparisons demonstrate a gene dosage effect of LMNA variants on the severity of fat loss and add to the body of evidence that there may be complex genotype-phenotype relationships in this interesting disease known as FPLD2. Although the pathological basis for fat loss is not well understood in patients harboring pathogenic variants in the LMNA gene, our observation suggests that genetic factors modulate the extent of fat loss in LMNA associated lipodystrophy.

A serendipitous discovery: an adult case of congenital generalized lipodystrophy

Congenital generalized lipodystrophies are a heterogeneous group of rare disorders characterized by loss of subcutaneous fat, muscular hypertrophy, acanthosis nigricans, hepatomegaly, cardiac arrhythmias, impaired metabolism, and mental retardation. We report a 41-year-old female that presented as a rare adult case of congenital generalized lipodystrophy type 1. She was referred to us as a case of hypertriglyceridemia with features of generalized lipodystrophy and manifestations of associated multiple metabolic disorders. Triglyceride level was tremendously high with reduced high-density lipoproteins. The patient was found to have a pathogenic novel mutation in the AGPAT2 gene, confirming the diagnosis of congenital generalized lipodystrophy type 1.

Changes in redox and endoplasmic reticulum homeostasis are related to congenital generalized lipodystrophy type 2

CGL type 2 is a rare autosomal recessive syndrome characterized by an almost complete lack of body fat. CGL is caused by loss-of-function mutations in both alleles of the BSCL2 gene that codifies to seipin. Subjects often show hyperglycemia, decreased HDL-c, and hypoadiponectinemia. These laboratory findings are important triggers for changes in redox and ER homeostasis. Therefore, our aim was to investigate whether these intracellular mechanisms are associated with this syndrome. We collected blood from people from Northeastern Brazil with 0, 1, and 2 mutant alleles for the rs786205071 in the BSCL2 gene. Through the qPCR technique, we evaluated the expression of genes responsible for triggering the antioxidant response, DNA repair, and ER stress in leukocytes. Colorimetric tests were applied to quantify lipid peroxidation and to evaluate the redox status of glutathione, as well as to access the panorama of energy metabolism. Long extension PCR was performed to observe leukocyte mitochondrial DNA lesions, and the immunoblot technique to investigate plasma adiponectin concentrations. Subjects with the rs786205071 in both BSCL2 alleles showed increased transcription of NFE2L2, APEX1, and OGG1 in leukocytes, as well as high concentrations of malondialdehyde and the GSSG:GSH ratio in plasma. We also observed increase of mitochondrial DNA lesions and XBP1 splicing, as well as a decrease in adiponectin and HDL-c. Our data suggest the presence of lipid lesions due to changes in redox homeostasis in that group, associated with increased levels of mitochondrial DNA damage and transcriptional activation of genes involved with antioxidant response and DNA repair.

Berardinelli Seip Congenital Lipodystrophy Syndrome: 10 Year Follow-up

Lipodystrophy syndromes are extremely rare disorders of deficient body fat associated with potentially serious metabolic complications. Here, we describe a 10-year-old girl with genetically proven Berardinelli Seip congenital generalized lipodystrophy type 2, diagnosed at 10 months of age. She developed comorbidities like proteinuria, hypertension, diabetes mellitus, and liver fibrosis.

Bowel perforation in a pediatric patient with congenital generalized lipodystrophy type 4

Abstract Congenital generalized lipodystrophy (CGL) is a rare autosomal recessive disorder that affects adipocyte development. Presentation varies based on type. A 12-year old female with CGL type 4, developed a sigmoid colon perforation in the setting of colonic wall hypertrophy after colonoscopy. She presented to the emergency room (ER) with several days of worsening abdominal pain and fevers. The initial evaluation was concerning for infectious versus inflammatory colitis. She was admitted for gastroenterology (GI) consultation for the complaint of abdominal pain. The patient had an established history of constipation management with laxatives. Full GI evaluation, including infectious panel as well as esophagogastroduodenoscopy (EGD) and colonoscopy, was negative. During the colonoscopy some difficulty with passage of the colonoscope past 25 cm was reported and therefore a gastroscope was used. She met criteria to start a clear liquid diet following the procedure. Two days after the colonoscopy, she had pneumoperitoneum on abdominal radiographs and was taken to the operating room for exploratory laparotomy. At the time of surgery, copious fibrinopurulent exudate was found throughout the abdominal cavity, as well as a thickened sigmoid colon/rectum and perforation with a contained abscess at the rectosigmoid junction. Sigmoid colectomy and end colostomy were performed. Pathologic examination demonstrated diffuse colonic wall thickening, a serosal defect that did not extended to the mucosa and several early diverticula. The pathology report stated that the presence of microscopic perforations could not be ruled out. The patient had an uneventful post-operative recovery. Congenital generalized lipodystrophy type 4 is a rare disease. We suspect an association between the muscular hypertrophy and the clinical presentation of bowel wall thickening and stricture. Given the rare nature of this disorder, clinicians that evaluate patients with CGL type 4 for constipation should have a suspicion for the possibility of colonic strictures. Rarely the condition can advance to perforation.

Metreleptin treatment for congenital generalized lipodystrophy type 4 (CGL4): a case report.

.Congenital generalized lipodystrophy type 4 (CGL4) is a rare disease caused by mutations in the gene polymerase I and transcript release factor (PTRF), the main symptoms of which are systemic reductions in adipose tissue and muscular dystrophy. The strategy of treating CGL4 is to improve the insulin resistance and hypertriglyceridemia that result from systemic reductions in adipose tissue. Metreleptin, a synthetic analog of human leptin, is effective against generalized lipodystrophies; however, there are no reports of the use of metreleptin in the treatment of CGL4. Herein, we discuss the treatment of a six-year-old boy diagnosed with CGL4 due to a homozygous mutation in PTRF with metreleptin. His serum triglyceride level and homeostasis model assessment of insulin resistance (HOMA-IR) value decreased after two months of metreleptin treatment. However, the efficacy of metreleptin gradually decreased, and the treatment was suspended because anaphylaxis occurred after the dosage administered was increased. Subsequently, his serum triglyceride level and HOMA-IR value significantly increased. Anti-metreleptin-neutralizing antibodies were detected in his serum, which suggested that these antibodies reduced the efficacy of metreleptin and caused increased hypersensitivity. Thus, metreleptin appeared to be efficacious in the treatment of CGL4 in the short term, although an adverse immune response resulted in treatment suspension. Further studies are needed to evaluate metreleptin treatments for CGL4.