Growth hormone deficiency and pituitary malformation in a recurrent Cat-Eye syndrome: a family report

Cat eye syndrome: Clinical, cytogenetics and familial findings in a large cohort of 43 patients highlighting the importance of congenital heart disease and inherited cases

Cat Eye Syndrome (CES) is a rare genetic disease caused by the presence of a small supernumerary marker chromosome derived from chromosome 22, which results in a partial tetrasomy of 22p-22q11.21. CES is classically defined by association of iris coloboma, anal atresia, and preauricular tags or pits, with high clinical and genetic heterogeneity. We conducted an international retrospective study of patients carrying genomic gain in the 22q11.21 chromosomal region upstream from LCR22-A identified using FISH, MLPA, and/or array-CGH. We report a cohort of 43 CES cases. We highlight that the clinical triad represents no more than 50% of cases. However, only 16% of CES patients presented with the three signs of the triad and 9% not present any of these three signs. We also highlight the importance of other impairments: cardiac anomalies are one of the major signs of CES (51% of cases), and high frequency of intellectual disability (47%). Ocular motility defects (45%), abdominal malformations (44%), ophthalmologic malformations (35%), and genitourinary tract defects (32%) are other frequent clinical features. We observed that sSMC is the most frequent chromosomal anomaly (91%) and we highlight the high prevalence of mosaic cases (40%) and the unexpectedly high prevalence of parental transmission of sSMC (23%). Most often, the transmitting parent has mild or absent features and carries the mosaic marker at a very low rate (<10%). These data allow us to better delineate the clinical phenotype associated with CES, which must be taken into account in the cytogenetic testing for this syndrome. These findings draw attention to the need for genetic counseling and the risk of recurrence.

SALL4 Phenotype in Four Generations of One Family: An Interplay of the Upper Limb, Kidneys, and the Pituitary

INTRODUCTION

The SALL4 gene encodes a transcription factor that is essential for early embryonic cellular differentiation of the epiblast and primitive endoderm. It is required for the development of neural tissue, kidney, heart, and limbs. Pathogenic SALL4 variants cause Duane-radial ray syndrome (Okihiro syndrome), acro-renal-ocular syndrome, and Holt-Oram syndrome. We report a family with vertical transmission of a SALL4 pathogenic variant leading to radial hypoplasia and kidney dystopia in several generations with additional growth hormone deficiency (GHD) in the proband.

CASE PRESENTATION

Our male proband was born at the 39th week of gestation. He was born small for gestational age (SGA; birth weight 2,550 g, -2.2 SDS; length 47 cm, -2.0 SDS). He had bilateral asymmetrical radial ray malformation (consisting of radial hypoplasia, ulnar flexure, and bilateral aplasia of the thumb) and pelvic kidney dystopia, but no cardiac malformations, clubfoot, ocular coloboma, or Duane anomaly. He was examined for progressive short stature at the age of 3.9 years, where his IGF-1 was 68 μg/L (-1.0 SD), and growth hormone (GH) after stimulation 6.2 μg/L. Other pituitary hormones were normal. A brain CT revealed normal morphology of the cerebral midline and the pituitary. He had a dental anomaly - a central mandibular ectopic canine. MRI could not be done due to the presence of metal after multiple corrective plastic surgeries of his hands. His mother's and father's heights are 152.3 cm (-2.4 SD) and 177.8 cm (-0.4 SD), respectively. His father has a milder malformation of the forearm. The affected paternal grandfather (height 164 cm; -2.3 SD) has a radial ray defect with missing opposition of the thumb. The family reports a similar phenotype of radial dysplasia in the paternal grandfather's mother. The proband started GH therapy at age 6.5 years when his height was 109 cm (-2.8 SDS) and he experienced catch-up growth as expected in GHD. Puberty started spontaneously at the age of 12.5 years. At age 13, his height was 158.7 cm (-0.2 SDS). Whole-exome sequencing revealed a nonsense variant in the SALL4 gene c.1717C>T (p.Arg573Ter) in the proband, his father, and paternal grandfather.

CONCLUSION

This is the first observation of a patient with a congenital upper limb defect due to a pathogenic SALL4 variant who has isolated GHD with no apparent cerebral or facial midline anomaly and has been successfully treated with growth hormone.

Congenital hypopituitarism and multiple midline defects in a newborn with non-familial Cat Eye syndrome

Background

Cat eye syndrome (CES) is a rare chromosomal disease, with estimated incidence of about 1 in 100,000 live newborns. The classic triad of iris coloboma, anorectal malformations, and auricular abnormalities is present in 40% of patients, and other congenital defects may also be observed. The typical associated cytogenetic anomaly relies on an extra chromosome, derived from an inverted duplication of short arm and proximal long arm of chromosome 22, resulting in partial trisomy or tetrasomy of such regions (inv dup 22pter-22q11.2).

Case presentation

We report on a full-term newborn, referred to us soon after birth. Physical examination showed facial dysmorphisms, including hypertelorism, down slanted palpebral fissures, and dysplastic ears with tragus hypoplasia and pre-auricular pit. Ophthalmologic evaluation and heart ultrasound identified left chorioretinal and iris coloboma and ostium secundum type atrial septal defect, respectively. Based on the suspicion of cat eye syndrome, a standard karyotype analysis was performed, and detected an extra small marker chromosome confirming the CES diagnosis. The chromosomal abnormality was then defined by array comparative genome hybridization (a-CGH, performed also in the parents), which identified the size of the rearrangement (3 Mb), and its de novo occurrence. Postnatally, our newborn presented with persistent hypoglycemia and cholestatic jaundice. Endocrine tests revealed congenital hypothyroidism, cortisol and growth hormone (GH) deficiencies, which were treated with replacement therapies (levotiroxine and hydrocortisone). Brain magnetic resonance imaging, later performed, showed aplasia of the anterior pituitary gland, agenesis of the stalk and ectopic neurohypophysis, confirming the congenital hypopituitarism diagnosis. She was discharged at 2 months of age, and included in a multidisciplinary follow-up. She currently is 7 months old and shows a severe global growth failure, and developmental delay. She started GH replacement treatment, and continues oral hydrocortisone, along with ursodeoxycholic acid and levothyroxine, allowing an adequate control of glycemic and thyroid profiles as well as of cholestasis.

Conclusions

CES phenotypic spectrum is wide and highly variable. Our report highlights how among the possible associated endocrine disorders, congenital hypopituitarism may occur, leading to persistent hypoglycemia and cholestasis. These patients should be promptly assessed for complete hormonal evaluations, in addition to major malformations and midline anomalies. Early recognition of such defects is necessary to decrease fatal events, as well as short and long-term related adverse outcomes.

Eye Signs in Pituitary Disorders

The eye is a vital sense organ and plays a vital role in conveying the underlying physical and mental state of wellbeing of an individual. A comprehensive examination of the eye is often required in patients presenting with systemic complaints. Many endocrine disorders have characteristic manifestations pertaining to the eye, the classical being the exophthalmos in thyrotoxicosis. However, a cursory eye evaluation may lead to the identification of early features that can help in the diagnosis of other endocrine disorders. This is more common in cases of pituitary mass lesions, who often present with the functional hormonal alterations rather than the visual symptoms. The definitive therapy during the late stages of the disease leads to persisting visual disabilities and affects the quality of life. Hence, the endocrinologists and ophthalmologists need to be aware of various ophthalmic features in the pituitary disorders. In this review, we highlight the eye signs in pituitary disorders, along with a brief description of uncommon ocular-pituitary syndromes.